Isothiocyanate Factor IX Polymer Conjugates
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Solution Overview
Problem
Current methods for conjugating Factor IX with polymers are complex, involve the use of oxidizers that can degrade the polymer and introduce unwanted oxidation, and are limited to specific polymers and regions on the Factor IX protein, leading to challenges in product stability and regulatory compliance.
Innovation Solution
Development of conjugates where Factor IX is covalently attached to a water-soluble polymer with a molecular weight between 5,000 and 150,000 Daltons, using linkages such as —CH2—C(O)—O—, —N(H)—C(O)CH2—O—, or —C(O)—N(H)—, allowing for simpler processes and broader polymer attachment options, including non-linear polymers, to enhance stability and regulatory compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If oxidizers are used to conjugate Factor IX with polymers, then conjugation can be achieved, but the polymer degrades and unwanted oxidation is introduced
Solution Approach 1:
The patent changes the chemical parameters of the conjugation process by using non-oxidizing conditions. Specifically, it employs isothiocyanate-functionalized polymers that react with amino groups on Factor IX through carbamoyl linkage formation, eliminating the need for oxidizing agents like periodate while achieving stable conjugation.
Solution Approach 2:
The patent introduces an intermediary functional group (isothiocyanate) that mediates the conjugation between polymer and Factor IX. This intermediary enables direct coupling through carbamoyl bond formation without requiring oxidizers, thus avoiding polymer degradation and unwanted oxidation side reactions.
2Ease of manufacture
If specific polymers and regions on Factor IX are used for conjugation, then conjugation can be achieved, but the process becomes limited and complex
Solution Approach 1:
The patent achieves universality by using isothiocyanate-functionalized polymers that can conjugate with any amino group on Factor IX, regardless of the specific region. This approach allows various polymer types and molecular weights to be used interchangeably, greatly enhancing versatility while simplifying the conjugation process.
Solution Approach 2:
The patent changes the conjugation strategy from region-specific to amino-group-general by utilizing the abundance of lysine residues throughout Factor IX. This parameter change in selectivity allows any polymer with isothiocyanate groups to conjugate effectively, removing limitations on polymer choice and conjugation site.
3Reliability
If Factor IX is conjugated with polymers, then stability and reduced immunogenicity are improved, but the process complexity increases
Solution Approach 1:
The patent uses isothiocyanate as an intermediary functional group that simplifies the conjugation process while achieving stable carbamoyl linkages. This intermediary enables direct reaction with amino groups on Factor IX without complex oxidation-reduction steps, reducing process complexity while maintaining conjugate stability.
Solution Approach 2:
The patent extracts the problematic oxidation steps from the conjugation process by using isothiocyanate chemistry instead. This removal of oxidizing agents and associated complex steps simplifies the overall process while preserving the stability benefits of polymer conjugation.
4Reliability
If frequent injections of Factor IX concentrate are administered, then hemophilia B treatment is maintained, but patient burden and allergic reactions increase
Solution Approach 1:
The patent applies dynamics by modifying Factor IX with polymers to change its pharmacokinetic properties. The polymer conjugation increases the molecular size and hydrophilicity of Factor IX, slowing its renal clearance and extending its half-life in circulation, thereby enabling less frequent dosing while maintaining therapeutic effectiveness.
Solution Approach 2:
The patent changes the physical parameters of Factor IX by conjugating with water-soluble polymers. This modification alters the molecular weight, hydrodynamic radius, and charge distribution of Factor IX, resulting in extended plasma half-life and reduced immunogenicity, which improves patient compliance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides stable and effective conjugates with improved bioavailability and reduced immunogenicity, enabling more efficient and safer treatment of hemophilia B by minimizing the need for frequent injections and reducing allergic reactions.
Implementation Method 1
a polymeric reagent is reacted with a Factor IX moiety to provide a conjugate
Data Source
AI summary
Conjugates of a Factor IX moiety and one or more water-soluble polymers are provided. Typically, the water-soluble polymer is poly(ethylene glycol) or a derivative thereof. Also provided (among other things) are compositions comprising the conjugates, methods of making the conjugates, and methods of administering to a patient compositions comprising the conjugates.